To provide a simple, lightweight, portable hair washer which enables a helper to wash hair of a bedridden old person as laying on a bed by him-/ her-self.

A hair washing room is made into a double room structure of upper and lower rooms. Hair is washed in the upper room and a drawer type drain tank is equipped in the lower room in a structure to enable waste water in the upper room is naturally flowed down into the drawer type drain tank in the lower room. Hair washing water is retained in a washing water tank on a stand detachably attached to a side part of the hair washing box or above a separately set pillar and supplied to a subject naturally flowing down through a flexible hose. After hair washing is finished, the stand, the tank, etc., are housed in the hair washing box for carrying.